/Engine/Plugins/Experimental/Water/Source/Runtime/Public/WaterBodyComponent.h
Returns what can be considered the single base Z of the water surface. Doesn't really make sense for non-flat water bodies likeEWaterBodyType::TransitionorEWaterBodyType::Riverbut can still be useful when using FixedZ for post-process, for example.
virtual float GetConstantSurfaceZ() const